A measuring roller bearing, in which a force acting on the roller bearing is detected by strain-sensitive sensors arranged on or in its stationary bearing shell, is known from DE 2746937 C2. These strain-sensitive sensors are designed as strain measuring resistors which are interconnected in a Wheatstone type measuring bridge.
Moreover, DE 100 41 093 A1 discloses a roller bearing with strain-sensitive sensors, with which inter alia the rotational speed of a rotatable roller bearing shell can be determined. These sensors are two mutually assigned strain measuring resistors or strain resistor measuring bridge circuits, which are provided on the stationary outer bearing shell. The two strain measuring strips can be arranged in relation to one another such that they are connected in series and are provided in the bearing shell so as to be offset in relation to one another in the direction of rotation by half the angular distance of the rolling elements. For measuring the rotational speed, provision is made such that the signal obtained from these two sensors when their attachment locations are rolled over by rolling elements is supplied to an evaluating circuit, in which the signals undergo difference formation. However, DE 100 41 093 does not indicate how the running direction of the balls of the roller bearing and thus the direction of rotation of a rotating bearing shell can be determined with this measuring bearing.
Lastly, a measuring arrangement in a roller bearing, with which the rotational speed and the running direction of the rolling elements in the bearing can be determined in addition to the force bearing upon the roller bearing, is known from DE 101 00 299 A1. This measuring arrangement is distinguished with regard to recognition of the direction of rotation by a number of pairs of strain-sensitive sensor elements being attached to or on a bearing shell at an angular distance from one another which is approximately ¼ of the angular distance of the rolling elements located in the roller bearing.
Moreover, the pairs of sensors are arranged on the bearing shell in an offset fashion in relation to one another such that they occupy, for examples, a 12 o'clock position and a 9 o'clock position. With an odd number of rolling elements in the bearing, it is ensured according to this specification that the measuring signals from the two sensor elements at the 12 o'clock position and those at the 9 o'clock position have a mutual phase offset. With the aid of this, the running direction of the rolling elements and thus also the direction of rotation of the displaceable bearing ring can be determined.
On the other hand, in an alternative embodiment, if an even number of rolling elements is present in the roller bearing, the running direction of the rolling elements can, according to DE 101 00 299 A1, be determined by the measuring signals from sensor pairs where the mutual angular offset of the sensor pairs deviates slightly from the 90° position between the sensors provided in the 12 o'clock position and in the 9 o'clock position.
For determining the running direction of the rolling elements, this specification discloses that an evaluating device is necessary, which receives signals generated by the two sensor elements of each sensor element pair and, from the amplitude of the signal modulation, determines the relative phase position of each of the rolling elements related to the sensor elements. The running direction of the components guided in the roller bearing can finally be inferred from this relative phase position.
This construction of the measuring arrangement for determining the direction of rotation of for example a component guided in a roller bearing is comparatively complicated. In particular, in the manufacture of such a measuring bearing, the application of the sensor elements of each sensor element pair and also the angularly accurate positioning of the sensor pairs in relation to one another requires a very careful and thus cost-intensive procedure.